Antioxidant and free radical-scavenging activities of chickpea protein hydrolysate (CPH)

Chickpea protein hydrolysate (CPH) was fractionated by gel filtration on Sephadex G-25. The antioxidant and free radical-scavenging activities of four CPH fractions (Fra.I, Fra.II, Fra.III, and Fra.IV) were measured using reducing power, inhibition of linoleic acid autoxidation, and 1,1-diphenyl-2- pycrylhydrazyl (DPPH)/superoxide/hydroxyl radical-scavenging assay. The antioxidant activity of Fra.IV (81.13%) was closer to that of alpha-tocopherol (83.66%) but lower than that of BHT (99.71%) in the linoleic acid oxidation system. Amino acid analyses showed that Fra.IV with the strongest antioxidant activity also had the highest total hydrophobic amino acids content (38.94% THAA) and hydrophobicity (125.62 kcal/mol amino acid residue) compared with the other three fractions. The molecular weight distribution of Frwa.IV was found to vary from 200 to 3000 Da. (C) 2007 Elsevier Ltd. All rights reserved.